FIG. 1 illustrates a MEMS switch 10 formed on a semiconductor substrate 12. The MEMS switch 10 includes an actuation member 14, such as the illustrated cantilever, which is may be formed from a conductive material. The actuation member 14 may have an anchored end 16, an arm 18, and a contact portion 20. Defined on the semiconductor substrate 12 are an anchor pad 22, an actuator plate 24, and a contact pad 26. The anchored end 16 of the actuation member 14 is attached and electrically coupled to the anchor pad 22. The arm 18 of the actuation member 14 is suspended over the actuator plate 24 and the contact portion 20 is suspended over the contact pad 26. To actuate the MEMS switch 10, an electric potential is generated between the actuator plate 24 and the arm 18. The electric potential creates an attractive force which pulls the arm 18 and thereby the contact portion 20 towards the semiconductor substrate 12. As a result, the actuation member 14 moves the contact portion 20 into electrical contact with the contact pad 26 to close the MEMS switch 10.
As shown in FIG. 1, the MEMS switch 10 is capped with a silicon (Si) or silicon dioxide (SiO2) cap 34. The cap 34 is attached to the semiconductor substrate 12 using layer 36 formed from a glass frit paste. On the exterior of the cap 34, the semiconductor substrate 12 has input/output pads 38 for connecting to the anchor pad 22, the actuator plate 24, and the contact pad 26. The problem with the design shown in FIG. 1 is its spatial inefficiency.
Referring now to FIG. 2, FIG. 2 illustrates a perspective view of the MEMS switch 10 shown in FIG. 1, which clearly demonstrates the spatial inefficiency of the MEMS switch 10. The MEMS switch 10 is excessively thick and may prevent flip chip assembly. Also, the glass frit layer 36 requires a large area. Exacerbating the spatial inefficiency of the MEMS switch 10 is the additional area of the semiconductor substrate 12 required to reveal the input/output pads 38 for the MEMS switch 10.
Thus, what is needed are more spatially efficient MEMS switches and methods of manufacturing the same.